7857381021 has 8 divisors (see below), whose sum is σ = 11973152064. Its totient is φ = 4489932000.

The previous prime is 7857380929. The next prime is 7857381029. The reversal of 7857381021 is 1201837587.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 7857381021 - 2⁷ = 7857380893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7857381029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 187080480 + ... + 187080521.

It is an arithmetic number, because the mean of its divisors is an integer number (1496644008).

Almost surely, 2^7857381021 is an apocalyptic number.

It is an amenable number.

7857381021 is a deficient number, since it is larger than the sum of its proper divisors (4115771043).

7857381021 is a wasteful number, since it uses less digits than its factorization.

7857381021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 374161011.

The product of its (nonzero) digits is 94080, while the sum is 42.

The square root of 7857381021 is about 88641.8694579486. The cubic root of 7857381021 is about 1988.0437515758.

The spelling of 7857381021 in words is "seven billion, eight hundred fifty-seven million, three hundred eighty-one thousand, twenty-one".